NSM: Avoid return code checking in NSM XDR encoder functions

Clean up.

The trend in the other XDR encoder functions is to BUG() when encoding
problems occur, since a problem here is always due to a local coding
error.  Then, instead of a status, zero is unconditionally returned.

Update the NSM XDR encoders to behave this way.

To finish the update, use the new-style be32_to_cpup() and
cpu_to_be32() macros, and compute the buffer sizes using raw integers
instead of sizeof().  This matches the conventions used in other XDR
functions

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Tested-by: J. Bruce Fields <bfields@redhat.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

1 files changed, 25 insertions, 43 deletions

diff --git a/fs/lockd/mon.c b/fs/lockd/mon.c
index e0c918949644..d812818d0258 100644
--- a/fs/lockd/mon.c
+++ b/fs/lockd/mon.c
@@ -401,26 +401,22 @@ void nsm_release(struct nsm_handle *nsm)
  * Status Monitor wire protocol.
  */
 
-static int encode_nsm_string(struct xdr_stream *xdr, const char *string)
+static void encode_nsm_string(struct xdr_stream *xdr, const char *string)
 {
         const u32 len = strlen(string);
         __be32 *p;
 
-        if (unlikely(len > SM_MAXSTRLEN))
-                return -EIO;
-        p = xdr_reserve_space(xdr, sizeof(u32) + len);
-        if (unlikely(p == NULL))
-                return -EIO;
+        BUG_ON(len > SM_MAXSTRLEN);
+        p = xdr_reserve_space(xdr, 4 + len);
         xdr_encode_opaque(p, string, len);
-        return 0;
 }
 
 /*
  * "mon_name" specifies the host to be monitored.
  */
-static int encode_mon_name(struct xdr_stream *xdr, const struct nsm_args *argp)
+static void encode_mon_name(struct xdr_stream *xdr, const struct nsm_args *argp)
 {
-        return encode_nsm_string(xdr, argp->mon_name);
+        encode_nsm_string(xdr, argp->mon_name);
 }
 
 /*
@@ -429,35 +425,25 @@ static int encode_mon_name(struct xdr_stream *xdr, const struct nsm_args *argp)
  * (via the NLMPROC_SM_NOTIFY call) that the state of host "mon_name"
  * has changed.
  */
-static int encode_my_id(struct xdr_stream *xdr, const struct nsm_args *argp)
+static void encode_my_id(struct xdr_stream *xdr, const struct nsm_args *argp)
 {
-        int status;
         __be32 *p;
 
-        status = encode_nsm_string(xdr, utsname()->nodename);
-        if (unlikely(status != 0))
-                return status;
-        p = xdr_reserve_space(xdr, 3 * sizeof(u32));
-        if (unlikely(p == NULL))
-                return -EIO;
-        *p++ = htonl(argp->prog);
-        *p++ = htonl(argp->vers);
-        *p++ = htonl(argp->proc);
-        return 0;
+        encode_nsm_string(xdr, utsname()->nodename);
+        p = xdr_reserve_space(xdr, 4 + 4 + 4);
+        *p++ = cpu_to_be32(argp->prog);
+        *p++ = cpu_to_be32(argp->vers);
+        *p = cpu_to_be32(argp->proc);
 }
 
 /*
  * The "mon_id" argument specifies the non-private arguments
  * of an NSMPROC_MON or NSMPROC_UNMON call.
  */
-static int encode_mon_id(struct xdr_stream *xdr, const struct nsm_args *argp)
+static void encode_mon_id(struct xdr_stream *xdr, const struct nsm_args *argp)
 {
-        int status;
-
-        status = encode_mon_name(xdr, argp);
-        if (unlikely(status != 0))
-                return status;
-        return encode_my_id(xdr, argp);
+        encode_mon_name(xdr, argp);
+        encode_my_id(xdr, argp);
 }
 
 /*
@@ -465,28 +451,23 @@ static int encode_mon_id(struct xdr_stream *xdr, const struct nsm_args *argp)
  * by the NSMPROC_MON call. This information will be supplied in the
  * NLMPROC_SM_NOTIFY call.
  */
-static int encode_priv(struct xdr_stream *xdr, const struct nsm_args *argp)
+static void encode_priv(struct xdr_stream *xdr, const struct nsm_args *argp)
 {
         __be32 *p;
 
         p = xdr_reserve_space(xdr, SM_PRIV_SIZE);
-        if (unlikely(p == NULL))
-                return -EIO;
         xdr_encode_opaque_fixed(p, argp->priv->data, SM_PRIV_SIZE);
-        return 0;
 }
 
 static int xdr_enc_mon(struct rpc_rqst *req, __be32 *p,
                        const struct nsm_args *argp)
 {
         struct xdr_stream xdr;
-        int status;
 
         xdr_init_encode(&xdr, &req->rq_snd_buf, p);
-        status = encode_mon_id(&xdr, argp);
-        if (unlikely(status))
-                return status;
-        return encode_priv(&xdr, argp);
+        encode_mon_id(&xdr, argp);
+        encode_priv(&xdr, argp);
+        return 0;
 }
 
 static int xdr_enc_unmon(struct rpc_rqst *req, __be32 *p,
@@ -495,7 +476,8 @@ static int xdr_enc_unmon(struct rpc_rqst *req, __be32 *p,
         struct xdr_stream xdr;
 
         xdr_init_encode(&xdr, &req->rq_snd_buf, p);
-        return encode_mon_id(&xdr, argp);
+        encode_mon_id(&xdr, argp);
+        return 0;
 }
 
 static int xdr_dec_stat_res(struct rpc_rqst *rqstp, __be32 *p,
@@ -504,11 +486,11 @@ static int xdr_dec_stat_res(struct rpc_rqst *rqstp, __be32 *p,
         struct xdr_stream xdr;
 
         xdr_init_decode(&xdr, &rqstp->rq_rcv_buf, p);
-        p = xdr_inline_decode(&xdr, 2 * sizeof(u32));
+        p = xdr_inline_decode(&xdr, 4 + 4);
         if (unlikely(p == NULL))
                 return -EIO;
-        resp->status = ntohl(*p++);
-        resp->state = ntohl(*p);
+        resp->status = be32_to_cpup(p++);
+        resp->state = be32_to_cpup(p);
 
         dprintk("lockd: xdr_dec_stat_res status %d state %d\n",
                         resp->status, resp->state);
@@ -521,10 +503,10 @@ static int xdr_dec_stat(struct rpc_rqst *rqstp, __be32 *p,
         struct xdr_stream xdr;
 
         xdr_init_decode(&xdr, &rqstp->rq_rcv_buf, p);
-        p = xdr_inline_decode(&xdr, sizeof(u32));
+        p = xdr_inline_decode(&xdr, 4);
         if (unlikely(p == NULL))
                 return -EIO;
-        resp->state = ntohl(*p);
+        resp->state = be32_to_cpup(p);
 
         dprintk("lockd: xdr_dec_stat state %d\n", resp->state);
         return 0;